More updates to PTTT

The Python Testing Tools Taxonomy Wiki has seen more updates recently. Here are some examples:

• Kent Johnson added two "miscellaneous" Python testing tools: HeapPy, written by Sverker Nilsson, and PySizer, written by Nick Smallbone; both tools aid in debugging, profiling and optimizing memory usage issues in Python programs
• Ned Batchelder added Pester, a Python port of a very interesting Java tool called Jester, written by Ivan Moore; the idea behind Jester is to mutate the source code, then run your unit tests and find those tests that don't fail and should fail
• Dave Kirby added Python Mock, a tool he wrote that enables the easy creation of mock objects
• Inspired by Dave's reference to mock objects, I added another mock-related Python tool I came across: pMock, written by Graham Carlyle and inspired by the Java jMock library